Segment Reporting (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2022 USD ($) segment	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Segment reporting
Number of reportable segments | segment	2
Total revenues	$ 1,283,566	$ 1,383,212	$ 1,632,026
Expenses:
Property operating expenses	1,109,070	1,091,812	1,236,357
Depreciation and amortization	239,280	271,131	270,147
General and administrative	26,435	34,087	30,593
Acquisition and certain other transaction related costs	2,605	17,506	814
Impairment of assets	0	(174)	106,972
Total expenses	1,377,390	1,414,362	1,644,883
Gain (loss) on sale of properties	321,862	492,272	6,487
Gains and losses on equity securities, net	(25,660)	(42,232)	34,106
Interest and other income	15,929	20,635	18,221
Interest expense	(209,383)	(255,759)	(201,483)
Gain on lease termination	0	0	22,896
Gain (loss) on modification or early extinguishment of debt	(30,043)	(2,410)	(427)
(Loss) income from continuing operations before income tax expense and equity in net earnings of investees	(21,119)	181,356	(133,057)
Income tax expense	(710)	(1,430)	(1,250)
Equity in net earnings of investees	6,055	0	0
Net (loss) income	(15,774)	179,926	(134,307)
Net income attributable to noncontrolling interest		(5,411)	(5,146)
Net (loss) income attributable to common shareholders	(15,774)	174,515	(139,453)
Total assets	6,002,093	6,623,514	6,476,424
Non-Segment
Segment reporting
Total revenues	38,350	40,992	43,850
Expenses:
Property operating expenses	671	0	0
Depreciation and amortization	11,343	11,455	11,702
General and administrative	26,435	34,087	30,593
Acquisition and certain other transaction related costs	2,605	17,506	814
Impairment of assets		0	0
Total expenses	41,054	63,048	43,109
Gain (loss) on sale of properties	0	0	4,517
Gains and losses on equity securities, net	(25,660)	(42,232)	34,106
Interest and other income	11,602	1,081	736
Interest expense	(206,936)	(230,193)	(175,072)
Gain on lease termination			22,896
Gain (loss) on modification or early extinguishment of debt	(30,059)	(2,410)	(26)
(Loss) income from continuing operations before income tax expense and equity in net earnings of investees	(253,757)	(295,810)	(112,102)
Income tax expense	(710)	(1,430)	(1,250)
Equity in net earnings of investees	0
Net (loss) income	(254,467)	(297,240)	(113,352)
Net income attributable to noncontrolling interest		0	0
Net (loss) income attributable to common shareholders		(297,240)	(113,352)
Total assets	887,064	1,345,043	471,565
Office Portfolio
Expenses:
Equity in net earnings of investees	6,055
Office Portfolio | Operating Segments
Segment reporting
Total revenues	222,390	367,597	383,365
Expenses:
Property operating expenses	94,299	127,313	129,756
Depreciation and amortization	76,007	127,632	129,321
General and administrative	0	0	0
Acquisition and certain other transaction related costs	0	0	0
Impairment of assets		0	8,558
Total expenses	170,306	254,945	267,635
Gain (loss) on sale of properties	321,040	492,072	2,597
Gains and losses on equity securities, net	0	0	0
Interest and other income	0	0	0
Interest expense	(913)	(23,477)	(24,188)
Gain on lease termination			0
Gain (loss) on modification or early extinguishment of debt	16	0	(401)
(Loss) income from continuing operations before income tax expense and equity in net earnings of investees	372,227	581,247	93,738
Income tax expense	0	0	0
Net (loss) income	378,282	581,247	93,738
Net income attributable to noncontrolling interest		(5,411)	(5,146)
Net (loss) income attributable to common shareholders		575,836	88,592
Total assets	1,967,244	2,282,652	3,092,289
SHOP
Expenses:
Interest and other income	4,327	19,554
Equity in net earnings of investees	0
SHOP | Operating Segments
Segment reporting
Total revenues	1,022,826	974,623	1,204,811
Expenses:
Property operating expenses	1,014,100	964,499	1,106,601
Depreciation and amortization	151,930	132,044	129,124
General and administrative	0	0	0
Acquisition and certain other transaction related costs	0	0	0
Impairment of assets		(174)	98,414
Total expenses	1,166,030	1,096,369	1,334,139
Gain (loss) on sale of properties	822	200	(627)
Gains and losses on equity securities, net	0	0	0
Interest and other income			17,485
Interest expense	(1,534)	(2,089)	(2,223)
Gain on lease termination			0
Gain (loss) on modification or early extinguishment of debt	0	0	0
(Loss) income from continuing operations before income tax expense and equity in net earnings of investees	(139,589)	(104,081)	(114,693)
Income tax expense	0	0	0
Net (loss) income	(139,589)	(104,081)	(114,693)
Net income attributable to noncontrolling interest		0	0
Net (loss) income attributable to common shareholders		(104,081)	(114,693)
Total assets	3,147,785	2,995,819	2,912,570
Rental income
Segment reporting
Total revenues	260,740	408,589	427,215
Rental income | Non-Segment
Segment reporting
Total revenues	38,350	40,992	43,850
Rental income | Office Portfolio | Operating Segments
Segment reporting
Total revenues	222,390	367,597	383,365
Rental income | SHOP | Operating Segments
Segment reporting
Total revenues	0	0	0
Residents fees and services
Segment reporting
Total revenues	1,022,826	974,623	1,204,811
Residents fees and services | Non-Segment
Segment reporting
Total revenues	0	0	0
Residents fees and services | Office Portfolio | Operating Segments
Segment reporting
Total revenues	0	0	0
Residents fees and services | SHOP | Operating Segments
Segment reporting
Total revenues	$ 1,022,826	$ 974,623	$ 1,204,811